{"product_id":"vaillant-diverter-valve-refurbished-252457","title":"Vaillant Diverter Valve – Refurbished | Part No. 252457","description":"\u003cp\u003eWhen a Vaillant combi boiler stops producing hot water on demand, defaults to heating only, or begins switching erratically between modes, a worn or seized diverter valve is frequently the cause. Part No. 252457 is the later-generation Vaillant diverter valve, used across a wide range of ecoTEC Plus, ecoTEC Pro, and ecoFIT models. As the valve's internal seals age and the spindle accumulates limescale, the valve can stick partially open, fail to actuate fully, or develop a slow internal bypass that reduces DHW output and heating efficiency simultaneously. The \u003cstrong\u003eVaillant Diverter Valve (Part No. 252457)\u003c\/strong\u003e is the correct OEM replacement for fully restoring combi operation.\u003c\/p\u003e\n\n\u003cp\u003eThis is a professionally refurbished genuine Vaillant component. Each valve is fully stripped — all internal seals, O-rings, and the valve spindle are inspected and replaced where required. The valve is reassembled, pressure-tested for hydraulic integrity, and electrically function-cycled through multiple actuation sequences to confirm full-travel, positive switching in both directions before dispatch. The 252457 is the direct replacement for the earlier 178978 on many models, offering a wider compatibility range across the ecoTEC product family.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCompatible Boiler Models\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003cth style=\"padding:8px;border:1px solid #ddd;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"padding:8px;border:1px solid #ddd;\"\u003eGC No.\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003eVaillant ecoTEC Plus 831\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003e47-583-21\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003eVaillant ecoTEC Plus 837\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003e47-583-22\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003eVaillant ecoTEC Plus 838\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003e47-583-23\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003eVaillant ecoTEC Plus 841\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003e47-583-24\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003eVaillant ecoTEC Pro 28\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003e47-583-01\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003eVaillant ecoTEC Pro 30\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003e47-583-02\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003eVaillant ecoFIT Pure 625\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003e47-583-30\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003eVaillant ecoFIT Pure 630\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ddd;\"\u003e47-583-31\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOEM Quality. Proven Performance. Backed by Warranty.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eEvery refurbished Vaillant diverter valve in our range is pressure-tested and cycle-verified before dispatch. This 252457 valve restores positive, reliable CH-to-DHW switching, eliminates stuck-valve and bypass-leak symptoms, and returns the boiler to full combi operation. As the updated replacement for the earlier 178978 design, it offers improved seal longevity on applicable models. Supplied with a full \u003cstrong\u003e12-month warranty\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDelivery \u0026amp; Returns\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOrders placed before \u003cstrong\u003e1:00 PM (Mon–Fri)\u003c\/strong\u003e are dispatched the same working day, with standard (2–3 working days), next-day, and Saturday delivery options available at checkout. Returns are accepted within \u003cstrong\u003e30 days\u003c\/strong\u003e, provided the item is unused and in its original packaging.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eNote:\u003c\/strong\u003e Please confirm that part number \u003cstrong\u003e252457\u003c\/strong\u003e matches your existing valve before ordering. On some models this part supersedes 178978 — check your boiler's current parts list if unsure. Installation must be carried out by a \u003cstrong\u003eGas Safe registered engineer\u003c\/strong\u003e to ensure safety compliance and warranty validity.\u003c\/p\u003e","brand":"Vaillant","offers":[{"title":"Refurbished","offer_id":48001086849189,"sku":"DIV-2457-A-BC","price":33.49,"currency_code":"GBP","in_stock":true}],"url":"https:\/\/ephsuppliers.com\/products\/vaillant-diverter-valve-refurbished-252457","provider":"Elite Plumbing \u0026 Heating Suppliers Ltd","version":"1.0","type":"link"}